docs: def _add_unqualified_edge(self, source: Node, target: Node, key: str, bel: str, data: EdgeData) -> Edge:
          """Add an unqualified edge to the network."""
          return self.get_or_create_edge(
              source=source,
              target=target,
              relation=data[RELATION],
              bel=bel,
              sha512=key,
              data=data,
          )